The Inside Skinny on Insider Trading

An expert weighs in on how useful this information is in predicting stock values.

FOLLOWING THE ARREST of hedge-fund manager Raj Rajaratnam on allegations of widespread illegal insider trading, a debate has raged about insider trading and the regulations that govern it.

While some observers have applauded the government's crackdown, others have argued that illegal insider trading is common and impossible to police. Some even argue that illegal insider trading plays a positive role in keeping markets efficient.